Envelope

ABSTRACT

An envelope of at least two parallel layers ( 1   a,    1   b ) of flat material, which are folded about a fold line ( 2 ), in which the envelope is closed on all the side edges and is delimited in a straight line on two side edges ( 3   a,    3   b ), the layers on the two side edges ( 3   c,    3   d ) lying opposite the straight side edges have a glueing region and at least one of these side edges is profiled, is characterized in that the two glueing regions run parallel throughout to the respective side edge and in a cohesive L-shaped region ( 4 ), one leg ( 4   a ) of which adjoins parallel onto the fold line, and that the other leg ( 4   b ) has a glueing region which does not reach up to the side edge ( 3   c ), so that on this side edge, before the folding of the envelope, a transport strip ( 5 ), running parallel to the glueing region, remains free of adhesive. Hereby, the envelope can be profiled on any desired side edge or on two side edges adjoining each other diagonally, without a gap which is free of adhesive occurring in one of the glueing regions.

The invention relates to an envelope of at. least two parallel layers of flat material, in particular paper, which are folded towards each other from a flatly lying blank about a shared fold line through 180°, in which the envelope, in the despatch state, is closed on all side edges and is delimited in a straight line on two side edges, at least one side edge lying opposite the side edges which are delimited in a straight line has a profiled form deviating from linearity in the folded state of the envelope, and in which the layers on the two side edges lying opposite the side edges which are delimited in a straight line respectively have a glueing area.

Such an envelope is known from DE 298 17 687 U1.

Conventional envelopes generally consist of two layers of paper which are folded towards each other about the fold line from a rectangular flat blank and are glued by means of glueing flaps on the two side edges adjoining onto the fold line. The side edge lying opposite the fold line normally also has a hinged flap which is likewise glued after the envelope has been filled, so that the content of the letter is situated in a flat space, closed off on all sides, between the two layers of paper. Starting from a substantially rectangular blank, these known envelopes then likewise have a rectangular contour, delimited by four straight side edges.

In order to give such envelopes a visually more interesting design, it is proposed in the above-mentioned DE 298 17 687 U1 that at least one of the side edges has a profiled form, deviating from linearity, for example in the form of curves, arcs, corners, continuous series of lines or suchlike. Preferably, according to DE 298 17 687 U1precisely one side edge, and namely the side edge lying opposite the fold edge is to be arranged in profiled form and in the folded state of the envelope between two narrow sides.

So that the profiling can reach an appreciable depth and can also follow imaginative and undulating curves and is not only limited to a narrow marginal region more or less parallel to the originally straight side edge, a relatively wide glueing region must be provided parallel to this side edge, where the two layers can then be glued over a large area, after the folding of the blank about the fold line, and can be profiled into the glued surface. As the profiled side edge can not bear a closure tongue (in any case without an excessively great technical effort), this glueing also serves at the same time as a side closure of the envelope. If a further side edge is to be designed so as to be profiled, a glueing region is also provided on the flatly lying blank parallel to this side edge. If a side edge, running in a straight line, is now to lie respectively opposite the two profiled side edges, the two profiled side edges must adjoin each other, for geometric reasons, by means of a shared corner.

In the production of the envelope, the flatly lying blank is moved through various stations of a production arrangement, which is generally brought about by one or more conveyor rollers which are pressed onto the surface of the blank and run in the conveying direction on a path through the centre of the blank. This path runs either along the fold line or transversely to the fold line and parallel to the side edges onto which the fold line abuts perpendicularly. Of course, the conveyor rollers must not come in contact with the glueing region, because otherwise the blank could stick fast to the conveyor rollers. Therefore, no glue must be applied onto the blank in the region of the path of the conveyor rollers, whereby, however, the glueing region, if it runs transversely to this path, has a glue-free gap which also remains after the folding of the envelope.

In the known envelopes, this can only be avoided in that only a single side edge, namely one which runs parallel to the path of the conveyor rollers, is profiled. However, if the envelope is now to have not merely one but two profiled side edges, this “circumventing solution” is no longer possible, because then for the above-mentioned geometric reasons one of the two glueing regions must in all cases have to be crossed by the path of the conveyor rollers. So that in such a case at least one closure of the envelope on all sides remains guaranteed, the region parallel to the fold line can be selected exclusively as the glueing region transversely to the path of the conveyor rollers, because after the envelope has been completed, the fold edge acts as a closure edge even without glueing. This, in turn, is only possible, however, when the fold edge is not interrupted by a profiling, so that then still only one single side edge can be profiled, namely the side edge adjoining onto the fold edge diagonally. Otherwise, a further closure device would have to be provided expressly for the “adhesive gap” in the fold edge, so that in the closed state the envelope is also really “tight” on all sides, which then, however, would require a considerable additional expenditure

Compared with this, it is an object of the invention to design the generic envelope described in the introduction with as inexpensive technical modifications as possible so that it can be profiled on any desired side edge or on two side edges adjoining each other diagonally, without the adhesive-free gap, described above, occurring in one of the glueing regions.

This object is achieved according to the invention in a manner which is both surprisingly simple and effective, in that the two glueing regions on the flatly lying blank, before the profiling of at least one of the side edges, run in each case parallel throughout to the respective side edge and as a whole in a cohesive L-shaped region, one leg of which adjoins parallel onto the fold line, and in that the other leg of the L-shaped region, not adjoining onto the fold line, has a glueing region which does not reach up to the parallel side edge, so that on this side edge, before the envelope is folded, a transport strip running parallel to the glueing region remains free of adhesive.

The path of the conveyor rollers on the flatly lying blank can run on this transport strip during the manufacture of the envelope, so that the adhesive can be applied throughout onto both glueing regions of the L-shaped region and without an adhesive-free gap. In addition, this arrangement makes possible the selection of any of the four side edges which is desired as the profiled edge, in which the geometric condition merely has to be maintained that a further profiled side edge must adjoin onto this first profiled side edge diagonally. An enormous number of additional design possibilities of the outer contours of the envelope according to the invention is therefore opened up, compared with a conventional one.

The blank preferably has a substantially rectangular shape, in which the straight side edges are arranged at right-angles to each other. The envelope according to the invention can thereby be readily processed on conventional postal sorting- and franking equipment.

Advantageously, the transport strip will have a width of 5 to 20 mm, preferably between 10 and 15 mm, so that a sufficiently wide path for the conveyor rollers remains free of adhesive.

Developments of the invention are also to be preferred, in which the legs of the cohesive L-shaped glueing region have a width between 10 and 50 mm, particularly between 20 and 40 mm, preferably between 25 and 35 mm. This makes possible a correspondingly deep profiling of the side edge and therefore opens up corresponding space for a creative design of the outer contour of the envelope according to the invention.

A quite particularly preferred embodiment of the invention is distinguished in that the blank has an articulated closure flap in each case at both side edges, delimited in a straight line, of the first of the two layers, in which the first closure flap extends over the entire length a of the first side edge which adjoins onto the fold line which is shared with the second layer, and that the second closure flap on the other side edge, delimited in a straight line, is articulated with the first side edge over a length b beginning from the shared corner up to the start of the region of the second side edge, where the L-shaped glueing region abuts the second side edge or comes close to it, so that after the folding of the envelope, the second closure flap can only be folded in in a region which is not glued.

The first closure flap of length a, which lies opposite the transport strip, can also be used during the processing of the flatly lying blank as a further transport strip for a second conveyor roller, operating parallel to the first, whereby a symmetrical distribution of the pressure forces of the first and second conveyor rollers is achieved on both sides of the blank, and also a particularly reliable conveying movement of the blank which is to be processed.

In order to provide a sufficiently wide path for the second conveyor roller, in preferred further developments of this embodiment, the first closure flap will have a width between 15 and 30 mm, preferably between 22 and 25 mm.

A further development of these embodiments is advantageous, in which the first side edge of the first layer, delimited in a straight line, has a length a and the side edge of the second layer, delimited in a straight line and adjoining thereon on the blank via the shared fold line, has a length a-ε, whereby the folding in of the closure flap and the filling and removal of filling material is facilitated because of the rear side of the envelope which is thereby shortened.

A modification of this further development is to be particularly preferred, in which the further side edge of the second layer, delimited in a straight line, which is cohesive with the side edge, delimited in a straight line, of the length a-ε via a shared corner, in the region in which after the folding of the blank about the fold line the L-shaped glueing region of the first layer abuts onto the side edge of the second layer, delimited in a straight line, or comes close to it, has a projecting tongue which protrudes by a length ε with respect to the further side edge of the second layer, delimited in a straight line. This makes possible an exact, parallel meeting of the edges of the two layers with each other in the glueing region adjacent to the closure flap, which brings about a considerably improved aesthetic impression when the envelope is closed.

In a further particularly preferred embodiment of the invention, the L-shaped glueing region runs on one side not quite up to the side edge, delimited in a straight line, but rather stops a few millimetres beforehand, so that a small margin region remains free of adhesive between this leg of the glueing region and the corresponding side edge, delimited in a straight line, in order to reliably prevent adhesive from emerging when the two layers of the envelope are pressed together.

In an advantageous development of the invention, one leg of the L-shaped glueing region runs up to the fold line. In this way, even with a very flat contouring of the side edge containing the fold line, a complete closure of the envelope can be ensured in this region.

Finally, an embodiment of the envelope according to the invention is advantageous in which the corners of the flatly lying blank are shaped so as to be rounded. In addition to the improved aesthetic effect, this design facilitates the filling of the envelope, because in rounded corners, compared with pointed corners, a tilting of the corners is prevented or is at least made difficult.

Further features and advantages of the invention will become apparent from the following detailed description of an example embodiment of the invention with the aid of the figure of the drawings, showing details essential to the invention, and also from the claims. The individual features can each be realized individually on their own or severally in any desired combinations in variants of the invention.

In the diagrammatic drawings, an example embodiment of the invention and also an envelope according to the prior art are shown. Both are explained in further detail in the following description.

FIG. 1 shows a flatly lying blank with a glueing region formed according to the invention; and

FIG. 2 shows a blank for an envelope according to the prior art.

In order to obtain an envelope according to the invention from two parallel layers of flat material, for example paper, the two layers 1 a, 1 b of the flatly lying blank 1 illustrated in FIG. 1 must be folded towards each other through 180° about a shared fold line 2. The envelope is then closed in the dispatch state on all side edges 3 a, 3 b, 3 c, 3 d and is delimited in a straight line on two side edges 3 a, 3 b. At least one of the side edges 3 c, 3 d lying opposite the side edges 3 a, 3 b, delimited in a straight line, will have a profiled shape, deviating from linearity, in the folded state of the envelope, which shape, however, is not yet present in the flatly lying blank 1, as is illustrated in the drawing.

In the folded state of the envelope, on the two side edges 3 c, 3 d lying opposite the side edges 3 a, 3 b delimited in a straight line, the layers 1 a, 1 b each have a glueing region, in which the two glueing regions on the flatly lying blank 1, before the profiling of at least one of the side edges 3 c, 3 d run respectively parallel throughout to the respective side edge 3 c or 3 d and as a whole in a cohesive L-shaped region 4, the one leg 4 a of which adjoins parallel onto the fold line 2, and the other leg 4 b of which, not adjoining onto the fold line 2, has a glueing region which does not reach up to the parallel side edge 3 c, so that on this side edge 3 c, before the envelope is folded, a transport strip 5 running parallel to the glueing region remains free of adhesive.

On both side edges 3 a, 3 b, delimited in a straight line, of the first layer 1 a, the blank 1 has in each case an articulated closure flap 6 a or 6 b. The first closure flap 6 a extends over the entire length a of the first side edge 3 a which adjoins onto the fold line 2 which is shared with the second layer 1 b. The second closure flap 6 b on the other side edge 3 b, delimited in a straight line, extends over a length b beginning from the shared corner with the first side edge 3 a up to the start of the region of the second side edge 3 b, where the leg 4 b of the L-shaped glueing region 4 abuts onto the second side edge 3 b or comes close to it.

The first side edge 3 a, delimited in a straight line, of the first layer 1 a has a length a, and the side edge 3 a′, delimited in a straight line an adjoining thereon on the blank 1 via the shared fold line 2, of the second layer lb has a length a-ε. The further side edge 3 b′, delimited in a straight line, of the second layer 1 b, cohesive via a shared corner with the side edge 3 a′, delimited in a straight line, of the length a-ε, in the region in which after the folding of the blank 1 about the sold line 2 the L-shaped glueing region 4 of the first layer la abuts onto the side edge 3 b′, delimited in a straight line, of the second layer 1 b or comes close to it, has a projecting tongue 7 which protrudes by a length ε with respect to the further side edge 3 b′, delimited in a straight line, of the second layer 1 b.

In the example embodiment shown in FIG. 1, the leg 4 a of the L-shaped glueing region 4 on one side does not run up to the side edge 3 a, delimited in a straight line, so that a margin region 8 remains free of adhesive between this leg 4 a and the corresponding side edge 3 a, delimited in a straight line. This leg 4 a of the glueing region 4 runs on the longitudinal side up to the fold line 2.

Both the corners of the blank 1, which connect the various side edges 3 a, 3 b, 3 c, 3 d; 3 a′, 3 b′ of the two layers 1 a, 1 b with each other, and also the corners of the various tongues 6 a, 6 b, 7 are designed so as to be rounded in the embodiment of FIG. 1.

In FIG. 2 a blank 10 according to the prior art is illustrated, in which the first layer 10 a has two glueing regions 40 a, 40 b, on which they are glued flat with the second layer 10 b after folding about the fold line 20. The glueing regions 40 a, 40 b are separated from each other by a relatively wide region 50 which is free of adhesive, where on processing of the blank 10, the conveyor rollers of a production installation run over the blank 10. In this region 50, however, no glueing will be present in the finished envelope, i.e. a “gap” will occur, so that the envelope can not be profiled on the side edge 30 d formed by the fold line 20, but rather merely on the side edge 30 c adjoining thereto. Otherwise, a further closure device would have to be provided expressly for the region 50. 

1. An envelope of at least two parallel layers (1 a, 1 b) of flat material, particularly paper, which are folded towards each other from a flatly lying blank (1) about a shared fold line (2) through 180°, in which the envelope in the despatch state is closed on all side edges (3 a, 3 b, 3 c, 3 d; 3 a′, 3 b′) and is delimited in a straight line on two side edges (3 a, 3 b), in which at least one side edge (3 c, 3 d) lying opposite of the side edges (3 a, 3 b) delimited in a straight line, in the folded state of the envelope, has a profiled form deviating from linearity, and in which the layers (1 a, 1 b) on the two side edges (3 c, 3 d) lying opposite the side edges (3 a, 3 b) delimited in a straight line in each case having a glueing region, characterized in that the two glueing regions on the flatly lying blank (1), before the profiling of at least one of the side edges (3 c, 3 d) in each case run parallel throughout to the respective side edge (3 c, 3 d) and as a whole run in a cohesive L-shaped region (4), one leg (4 a) of which adjoins parallel onto the fold line (2), and that the other leg (4 b) of the L-shaped region (4), not adjoining onto the fold line (2), has a glueing region which does not reach up to the parallel side edge (3 c), so that on this side edge (3 c), before the folding of the envelope, a transport strip (5), running parallel to the glueing region, remains free of adhesive.
 2. The envelope according to claim 1, characterized in that has and that the straight side edges (3 a, 3 b) are arranged at right-angles to each other.
 3. The envelope according to claim 1, characterized in that the transport strip (5) has a width of 5 to 20 mm, preferably between 10 and 15 mm.
 4. The envelope according to claim 1, characterized in that the legs (4 a, 4 b) of the cohesive that the blank (1) a substantially rectangular shape L-shaped glueing region (4) have a width between 10 and 50 mm, particularly between 20 and 40 mm, preferably between 25 and 35 mm.
 5. The envelope according to claim 1, characterized in that the blank (1) on both side edges (3 a, 3 b), delimited in a straight line, of the first (1 a) of the two layers, in each case has an articulated closure flap (6 a, 6 b), in which the first closure flap (6 a) extends over the entire length a of the first side edge (3 a), which adjoins onto the fold line (2) shared with the second layer (1 b), and that the second closure flap (6 b) on the other side edge (3 b), delimited in a straight line, over a length b beginning from the shared corner is articulated with the first side edge (3 a) up to the start of the region of the second side edge (3 b), where the L-shaped glueing region (4) abuts onto the second side edge (3 b) or comes close to it.
 6. The envelope according to claim 5, characterized in that the first closure flap (6 a) has a width between 15 and 30 mm, preferably between 22 and 25 mm.
 7. The envelope according to claim 5, characterized in that the first side edge (3 a), delimited in a straight line, of the first layer (1 a) has a length a, and the side edge (3 a′), delimited in a straight line, adjoining thereto on the blank (1) via the shared fold line (2), of the second layer (1 b) has a length a-ε.
 8. The envelope according to claim 7, characterized in that the further side edge (3 b′), delimited in a straight line, cohesive with the side edge (3 a′) of the length a-ε, delimited in a straight line, via a shared corner, of the second layer (1 b) in the region in which after the folding of the blank (1) about the fold line (2) the L-shaped glueing region (4) of the first layer (1 a) abuts onto the side edge (3 b′), delimited in a straight line, of the second layer (1 b) or comes close to it, has a projecting tongue (7) which protrudes by a length ε with respect to the further side edge (3 b′), delimited in a straight line, of the second layer (1 b).
 9. The envelope according to claim 1, characterized in that the L-shaped glueing region (4) on one side does not run up to the side edge (3 a) delimited in a straight line, so that between this leg (4 a) of the glueing region (4) and the corresponding side edge (3 a) delimited in a straight line, a margin region (8) remains free of adhesive.
 10. The envelope according to claim 1, characterized in that a leg (4 a) of the L-shaped glueing region (4) runs up to the fold line (2).
 11. The envelope according to claim 1, characterized in that the corners of the flatly lying blank (1) are shaped so as to be rounded. 